Theory:

     The kind old man, hearing that his lord, the daimio, was to pass along the high road near the village, set out to see him, taking his basket of ashes. As the train approached, he climbed up into an old withered cherry tree that stood by the wayside.
 
     Now, in the days of the daimios, it was the custom, when their lord passed by, for all the loyal people to shut up their high windows. They even pasted them fast with a slip of paper, so as not to commit the impertinence of looking down on his lordship. All the people along the road would fall upon their hands and knees and remain prostrate until the procession passed by.
Explanation:
 
By the time the good old people were becoming famous with their magical ashes, there was an announcement that daimio was about to pass the high road near their village. Daimio refers to Japan's most powerful landowners from the tenth century until the nineteenth century.
 
The daimio and his wife.jpg
The daimio and his wife
 
Naturally, the good old man's kind heart wanted to greet his master on hearing the news and so started his journey with a basket of mill ashes in his hand. He climbed up onto an old withered cherry tree on the roadside as the train neared.
 
During the days of the daimios, it was common practice for all loyal people to close their high windows when their lord passed by their way as they were not supposed to look down on landlords. They even taped the windows with a piece of paper so they wouldn't look down on his lordship. Also, everyone on the road should get down on their knees and remain with their heads looking downward until the procession passed.
 
Meaning of difficult words:
 
S.No
Words
Meaning
1.
Impertinence
Rudeness
2.
Prostrate
Lying face downward
3.
Procession A line of people or vehicles moving in a formal way
Reference:
National Council of Educational Research and Training (2007). Honeycomb. The Ashes That Made Trees Bloom (pp. 55-63). Published at the Publication Division by the Secretary, National Council of Educational Research and Training, Sri Aurobindo Marg, New Delhi.